Large amounts of contaminated waste oil are generated in industrial and manufacturing operations. These oils can contain solid materials such as metal chips as well as nonlubricating, possibly slightly corrosive chemicals and water. Such waste oils are for example generated in auto repair shops and in machine shops. The collection and disposal of such waste oils involves high costs, since for this purpose few and expensive burning facilities are available and therefor high storage and transport cost are incurred.
In order to save such disposal costs smaller shops try frequently to burn waste oil in their own oil heating units. It has been found in practice that break-down of the oil burner pump or of the pressure controller rapidly occurs. A cause for this can be the solid particles transported in the waste oil as well as the inclusion of nonlubricating media in the stream of oil.
It is not uncommon that waste oils are disposed irresponsibly in the environment in order to save high disposal costs, the result being considerable damage to the environment.
A combustion system constructed solely for waste oils is for example known from Austrian Patent AT-PS 292-900. In the system the waste oil is transported by compressed air into a separator for solid particles and is transported from the separator by partial vacuum to the burner nozzle. The burner nozzle operates in accordance with the injector principle and sucks the waste oil from the separator.
A substantial disadvantage of this proposal is that in addition to the house or shop heating system a separate burner with a boiler or the like is required. Also the conditions of the combustion are unsatisfactory. In addition waste oils with a large water content cannot be combusted, since such an amount of heat is transferred to the oil feed line that the water in the water/oil emulsion evaporates. This interrupts the feed of oil and quenches the flame.